Engine protective device



April 20, 1926.

D. WHITSON ENGINE PROTECTIVE DEVICE Filed March 28, 1924 2 Sheets-Sheet 1 FIG. I.

FROM pu 7 ///////l///////////////////1I///// r y A 2 58." I v 1 INVENTOR DAVID E. wHrr'soN BY. [I r A TTORNEY- April 20, 1926. 1,581,767

D. E. wHlTsoN ENGINE PROTECTIVE DEVICE Filed March 28, 1924 2 Sheets- Sheet 2 FIG. 4

I N VEN TOR DAVID E. WHIITSON a? ATTORNEY Patented Apr. 20, 1926.

UNITED STATES 1,581,767 PATENT OFFICE.

DAVID E. WHITSON, OF ST. LOUIS, 'MISSOUBI:

ENGINE PROTECTIVE DEVICE.

Application filed March 28, 1924. Serial No. 702,707.

To allwhom it may concern:

Be it known that I, DAVID E. VVHITSON, a citizen of the United States, residing at St. Louis, in the State of Missouri, have invented certain new and useful Improvements in Engine Protective Devices, of which the following is a specification.

My invention has relation to improvements in engine protective devices and is directed more specifically to cutting off the fuel supply or ignition of an internal combustion engine should the oil supply fail.

It is well known that if the lubrication of a high speed internal combustion engine, such as is used in automobiles, should fail for any cause, such as exhausting the oil or inoperativeness of the pump, considerable harm would be done to the engine if permitted to operate in this condition. I have therefore provided a device that, responsive to the oil pressure, will cut off the fuel supply to the engine or the ignition thereof, if for any reason this pressure should fall below normal. The object of the present invention is thus to stop the engine almost immediately if the oil circulation fails or the oil level in the crankcase should fall below a safe level. A further object is to provide a device of this character that is simple, that may be applied to an engine without alterations thereof, and one that is positive in its action.

Further and other advantages will be better apparent from a detailed description thereof in connection with the accompanying drawings, in which Figure 1 is a side elevation of an engine in outline with my invention applied thereto; Fig. 2 is a middle longitudinal section through my protective device; Fig. 3 is cross-sectional detail taken on the line 33 of Fig. 2; Fig. 1 is a diagrammatic View of a modified form of the invention which operates to cut off the ignition if the oil supply gets below a safe level; Fig. 5 is a further modification in which the gasoline is cut off at the carbureter if the oil pressure falls below normal.

Referring to the drawings and for the present toFigures 1, 2 and 3, E represents an engine in outline provided with the-usual carbureter 1 fed from a vaccuum tank 2 through a pipe 3, and also provided with an oil pump 4 connected to an oil gauge 5 by a pipe 6, the gauge being connected to the engine by a pipe 7,

My improved protective device D which is connected to both the oil line and the fuel line may be described as follows:

8 represents a cylindrical housin vlded w th, a bore 9 and a bore 9 s larger, 9. should two bores join A rectangular enlargex-nentll is formed in any su1tab1e manner oniitlre-Lhousing 8 epposite about the middle of theibore 9', and transverse ports 12, 12. are provided in the enlarged housing wall 11, said port's communicating with the bore 9. A by-pass 13 is also provided in theenlargement 11, said by-pass communicating with the ports 12, 12. A set screw 14 is ada ted to enter the component 13 of the y-pass and operates as a yalve to close off the by-pass except in certain emergencies to be pointed out heremafter. The enlargement 11 is also provided with a bore 15 disposed perpendicular to by-pass 13 and parallel with bore 9, and a bent tube 16 is inserted in bore 15 and an opening 17 in the wall of housing 8 for the pur ose of connecting the by-pass 13 with the ores 9 and 9.

Arranged to operate within bore 9' is a plunger 18, said plunger being normally held in the position shown full in Fig. 2 by a coiled spring 19 which is confined between the plunger and a terminal enlargement 20 on an adjusting screw 21, which passes through a cap 22 onv the end of housing 8. A packing nut 23 is screwed over the stem of screw 21 into engagement with the cap 22 to prevent leakage of any fluid within the bore 9. A reducing coupling 24 is screwed over the end of housmg S-adjacent the plunger 18 to which any fitting, such as a T 25, may be connected for. the purpose of connecting this end ofhousing 8 to the oil pi 3e 6. There is a threadedboss 26911 each side of enlargement 11 through"whicli-..the port 12 passes, and these bosses are connected in the fuel pipe 3 by suitable fittings.

The plunger 18 is provided with an elongated port 27 that is positioned between the coupling 24 and ports 12, 12 so that the ports 12 12 are out of communication when the englne is idle, the plunger operating as a valve to close these ports. However, when pressure is exertedon the end of the plan or adjacent to coupling 24' the lunger will forced against the tension 0 spring 19 and its port 27 will move into register with ports 12, 12 thus bringing them, into er 10 resulting where the,

. is not running the plunger is in the communication. As soon as the pressure on the plunger falls below a certain point the s ring 19 will move the plunger back again c osing oif the ports 12, 12.

a The operation of the invention may now be described as follows: When the engine E position shown by full lines in Flgure 2 and t e ports 12, 12 are closed by the plunger, hence no fuel can flow through pipe 3 to the carbureter 1. However there is enough fuel in the float chamber of the carbureter to start the engine, after which operation the engine operates the pum 4. Now as soon as the oil pump 4 is operating it will force 011 throu'gh pipe 6, gauge 5, and pipe 7, and, since the coupling 24 is connected to pipe 6 the pressure in the oil line will force oil through this coupling and against the end of plunger 18 with the full pressure exerted by the oil pump 3, This oil pressure forces the plunger back in the bore 9' against the pressure of spring 19 until the port 27 comes into register with ports 12, 12 at which time the plunger is balanced between the oil pressure at one end and the spring pressure at the other. The port is elongated to make allowance for variations in the oil pressure due to the temperature thereof. At the same time should the oil be extremely thick on account of very low temperature so that it would exert an unusually high pressure on the plunger, said plunger will be arrested when it impinges on the shoulder 10 at which time ports 12, 12 will still be in communication. When the ports 12, 12 are in communication the fuel will pass through them from the vacuum tank 2 to the carbureter. Now, if for any reason the oil pressure against the plunger 18 falls below minimum working pressure the plunger will move toward coupling 24 and as soon as ports 27 and 12, 12 are out of register the fuel supply to the carbureter is cut off. Thus if the pump gets out of order or the oil level in the crankcase falls below low level the fuel supply is cut off and almost immediately the engine stops'running. In this event the operator will know at once (assuming he has fuel in the fuel tank) that his oil supply has failed, and he can correct the same before any damage can happen to the engine for lack of lubrication.

In view of the fact that the engine will stop running almost immediately that the oil circulation fails, it is desirable to have some means of restoring the fuel feed in emergencies. For instance, one may be driving some miles from the nearest habitation and would not care to stay in the road until the trouble can be corrected or oil obtained. In this event the car may be driven a short distance at the risk of burning out the bearings by si'mpl turning the valve screw 14 and opening t e by-pass 13 thus permitting past the plunger 18 into bore 9 it will be pumped out of this chamber, by the action of the plunger, through the tube 16 into by-lpass 13 and into outlet' port 12 to the car ureter.

In the event that oil may work past the plun er 18, I provide an annular groove 28 in which it may collect, draining back into the engine crank-case through a discharge opening 29 to which is connected atube 30.

It is a well knowii fact that the pressure in the lubricating system is not the same in all engines. Now in order that my device may be equally applicable to engines having a low oil pressure I provide means for modifying the connection to the oil line. This modified connection consists of a threaded boss 31 spaced from the coupling 24 about the same distance as the plunger 18 must move to open the fuel pipe 3, said boss having an opening 32 through it in communication with the bore 9'. Now, if the coupling 24 is connected directly to pipe 6 and the boss 31 to the oil gauge 5 by a suitable pipe -33 (dotted Fig. 2) the oil circulation must be through the coupling 24 and bore 9. Thus the plunger 18 is bound to move forward to uncover opening 32 so that the oil can circulate. When the oil pressure is sufiicient to operate the plunger without connecting to the boss 31, a cap 34 is screwed over said boss.

Referring now to Fig. 4, I show a type of engine that does not utilize a pump to circulate the oil in the crank-case 35. I therefore provide an oil float chamber 36 connected to the bottom of said crank-case by a pipe 37 and to the low-level pet cook tallic contact 43 from which a conductor 44 leads to the magneto point 45 or some other suitable part of the ignition system. Now since the member 45 is grounded on the engine and since the float chamber housing, with which float 40 contacts, is also grounded a short-circuit of the ignition is effected when contacts 42 and 43 are connected. This, of course, stops the engine. The electric connections from contact point may be varied if necessary as shown by the dotted lines (Fig. 4). That is, conductor 44 may lead to one side of the battery 46, a solenoid 47 being connected to the other side of the battery and the frame of the car (ground). Now, if contacts 42 and 43 are connected the solenoid will be energized and attract its plunger 48, said plunger pulling a switch 49 out of contact with switch point 50 and opening ignition circuit 51. As soon as the contacts 4:2 and 43 are separated 'a spring 52 pulls the switch 49 back in place to close said ignition circuit.

In Fig. 5 I show a modification wherein a pipe 53 is connected to the oil line at one end (not shown) the other end being conneoted to a pressure responsive element 54 terminating in a rack bar 55 adapted. to rotate a pinion 56 as it moves over said pinion. A lever arm 57 is secured to said pinion, the free end of said lever; being disposed slightly above the end of the carbureter needle Valve stem 58 when the element54; Should the 011 pressure fail the element 54 will contract and the pinion 56 will be rotated to oscillate the arm 57 downwardly. The arm 57 will then engage the top of the stem 58 and move said. stem down with it until the needle valve is closed and the flow of fuel to the carbureter shut ressure is on- In combination with an internal combustion engine provided with a fuel supply pipe and afpressure lubrication system, a housing connected in the fuel supply pipe, said housing having a fuel intake and a fuel discharge port, a ported plunger operative in said housing across said ports to normally close same, means for conducting the pressure in the lubrication system to the plunger to actuatethe same, means for resisting said pressure to a certain amount, said plunger being adapted to move to a position for bringing into register its port and the aforesaid fuel intake and discharge ports at an applied pressure in excess of said certain amount, and means for draining from the housing any lubricant that may escape past the plunger,

In testimony whereof I hereunto aflix my signature.

Davina. wHrrson.v 

